1. Field of Invention
The invention is directed to roller assemblies for transporting and lateral shifting pipe segments, or joints, such as on an offshore laybarge or onshore pipe spooling yard in the oil and gas exploration and production industry.
2. Description of Art
Typical laybarge and pipe spooling yards have a restriction on space. As a result, pipe segments, also referred to herein as pipe sections and pipe joints, are made-up prior to being run-in the wellbore or through the riser of an offshore platform or vessel by moving the individual pipe segments in an initial direction on roller assemblies, laterally moving the individual pipe segments to a second line of roller assemblies, and then moving the pipe segments in an opposite direction. This procedure is repeated until each pipe segment can be connected to another pipe segment. For example, a pipe joint may be initially stored on a storage rack. When the time comes to secure this pipe joint to another pipe joint, the pipe joint is transferred along a roller assembly from the storage stack toward the opposite end of the laybarge. The pipe joint is then laterally transferred from the first roller assembly to a second roller assembly or to the opposite side of a double roller assembly, i.e., a roller assembly having two independently rotatable rollers. Currently, the step of laterally moving each pipe segment requires the pipe segment to be lifted by a crane or other device and placed in the second roller assembly. The pipe joint can then be moved along this second roller assembly toward the end of the laybarge where the pipe joint was originally stored. This procedure can be repeated as necessary to move the pipe joint to the point where it is attached to another pipe joint prior to run-in.